1. Field of the Invention
The present disclosure relates to an image forming apparatus, such as a laser printer, a copy machine, or a facsimile machine, which is operable according to an electronic photographic recording method.
2. Description of the Related Art
An image forming apparatus (e.g., a copy machine or a laser printer) that performs operations according to an electronic photographic recording method is conventionally known. For example, the image forming apparatus performs the following electronic photographic processes according to the electronic photographic recording method. First, a charging device uniformly charges the surface of a photosensitive drum, for example, to have an electric potential of −600 V. Subsequently, a laser exposure device forms an electrostatic latent image on the photosensitive drum with laser light. Then, a developing device develops the electrostatic latent image with toner particles to form a toner image. A transfer device transfers the toner image onto a recording member.
Further, for example, as discussed in Japanese Patent Application Laid-Open No. 2001-281944, a drum cleaning device removes remaining toner particles off the photosensitive drum and a pre-exposure lamp irradiates the photosensitive drum with light to neutralize the drum surface as a preparation for the next image forming operation.
In forming an electrostatic latent image on a photosensitive member surface, controlling the charging potential of the photosensitive member surface beforehand is important for the above-mentioned image forming apparatus that is operable according to the electronic photographic recording method. For example, in performing the above-mentioned charging potential control, the above-mentioned pre-exposure lamp and other various control methods are available. However, it is desired to employ a simplified configuration that can reduce the costs of the entire apparatus and downsize the apparatus body.
The printers that are popular and mostly used in recent years are color printers. In general, the control for a color printer includes changing the processing speed to process various types of recording media (e.g., rough papers and gloss papers) in addition to plain papers. Further, in some cases, it is desired to differentiate the processing speed to be set for monochrome printing from the processing speed to be set for color printing. As mentioned above, the color printer is required to perform complicated operations/controls to realize various processing speeds.